| Anionic living polymerization was widely used,especially in preparing non-linear polymers with complicated structure.The development of high-performance rubber and nanoporous functional polymer materials started a new field of application of anionic polymerization.Novel tin coupled star-shaped medium vinyl butadiene rubber(S-MVBR)/star-shaped miktoarm polyisoprene-co-poly (styrene-co-butadiene)rubber(S-ISBR)were designed and synthesized by "arm-first" or "core-first" method of anionic polymerization,with SnCl4 and divinyl benzene as coupling agent.The coupling reaction and relations between structure and properties were studied.Meanwhile, multistage porous polystyrene was prepared by alcoholic-lithium association template and its micromorphology was investigated.The main achievements are as following:1.S-MVBR with favorable structure was designed and prepared by "core-first" method with multifunctional organolithium containing Sn atom as initiator.Compared with "arm-first" method by SnCl4,this process had many advantages:simple route,high coupling efficiency, excellent performance.The average arm number(AN)of S-MVBR is conveniently regulated between 2.5～4.5 by changing the mole ratio of active lithium to Cl- in SnCl4 from 2.2 to 1.6.The molecular weight distribution was widened to 1.4～5.8.And vinyl content(Bv%)can be controlled in 30%～55%by[THF]/[Li+](11～60).2.The performance and properties of S-MVBR was investigated and the results indicated:with increasing AN,hardness,300%modulus increased,tgδat 50℃～100℃decreased;with increasing By%, elongation at break,tear strength increased,wet grip was improved;with increasing molecular weight,300%modulus and resilience increased; the processing properties were improved obviously.The relations between properties and structure proved the rationality and validity of design of S-MVBR.S-MVBR is excellent tire tread with low rolling energy loss,low dynamic heating and processing properties.3.The "integral rubber" concept was introduced in order to obtain optimal comprehensive performances.Star miktoarm polyisoprene-copoly (styrene-co-butadiene)(S-(PI)n-(PSB)n)was synthesized by "arm-first " method and "core-first" method subsequently with DVB as coupling agent.Compared with "arm-first" method of SnCl4,this process had higher coupling efficiency and easier structure controllability.The coupling reaction of DVB with linear polyisoprene lithium was studied and the results showed as following:the coupling efficiency could be approach 70%～80%when impurities were reduced and isoprene participated in coupling;AN increased from 2 to 5 with[DVB]/[Li] increasing from 0.6 to 5.The following propagation of styrene-butadiene from star polyisoprene lithium revealed:the monomers mainly propagated from S-PI-(DVB)xLi at high coupling efficiency,whereas from L-PI-(DVB)xLi;total AN increased from 5 to 12;when[DVB]/[Li] approached to 5,coupling probability between star polymer increased and gel came into being.4.The star miktoarm polymer was characterized by DSC,TEM,DMTA and its mechanical properties were decided.The results showed: the microdomain of PI and PSB can be formed by regulating microstructure and component;high value area of tgδ～T curve was wider than SSBR and linear SIBR,tgδat 0℃reached to 0.26 and tgδat 60℃was below 0.08;mechanical properties corresponded to SSBR.All of these indicated that chemical bonding of PI and PSB increased the compatibility and the microdomain was much smaller than the NR/SBR blend,at the same time,independency of two kinds of chain wasn't disturbed,accordingly,the respective advantages of SSBR and NR were exerted in this kind of star miktoarm polymer.S-ISBR was a ideal integral rubber with excellent overall performances,i.e.,very low rolling resistance,higher wet grip,excellent mechanical and good processing properties.5.The multistage porous polystyrene was prepared by alcoholic-lithium association template.The process included three steps: aggregation of alcohol-lithium association in styrene;anionic in-situ polymerization of styrene with divinyl benzene at -18℃～0℃; disaggregation of alcohol-lithium aggregation from crosslinking PS by hydrochloric acid.The influence factors on morphology of cross-section of polystyrene matrix were discussed,such as preparing method,content and kinds of alcohol-lithium.The results showed that although lithium isopropoxide association could dissolve in styrene and solubility approached to[(CH3)2CHOLi]/[St]=1/5,volume shrinkage due to styrene polymerization drived the associations aggregation and the dimension of aggregates was about several hundred nanometer,only which near to cross-section or interface could disaggregate in hydrochloric acid.The further investigation revealed multistage porous morphology of 'Circuit board' form existed in polystyrene matrix at 0℃in spite of preparing sequences.And the channels of 3 micron were perpendicular each other. The channel wall was porous.The formation of multistage porous morphology was related to the rate of shrinkage,polymerization and aggregation.At -18℃"snowflake"' type porosity formed when [(CH3)2CHOLi]/[St]=1/5 and 10nm～50nm porosity formed when [(CH3)2CHOLi]/[St]=1/5.
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